According to a previous report published in Shephard Media, the ATLA railgun utilizes five megajoules (MJ), or five million joules (J), of charge energy. It can fire bullets at a speed of around 2,230m/s (Mach 6.5). 20 MJ of charge energy is what ATLA wants it to run on eventually.

This is the unbelievable part:

Additionally, interceptors can be fired by railguns at varying speeds. Operators can change the rate at which an interceptor moves by manipulating the amount of electrical power used. These choices would be based on how quickly incoming missiles approach.

https://www.eurasiantimes.com/historic-japan-becomes-1st-country-ever-to-fire-electromagnetic/

On Thu, 19 Oct 2023 08:33:29 -0700 (PDT), Fred Bloggs
<bloggs.fredbloggs.fred@gmail.com> wrote:

>According to a previous report published in Shephard Media, the ATLA railgun utilizes five megajoules (MJ), or five million joules (J), of charge energy. It can fire bullets at a speed of around 2,230m/s (Mach 6.5). 20 MJ of charge energy is what ATLA wants it to run on eventually.
>
>This is the unbelievable part:
>
>Additionally, interceptors can be fired by railguns at varying speeds. Operators can change the rate at which an interceptor moves by manipulating the amount of electrical power used. These choices would be based on how quickly incoming missiles approach.
>
>https://www.eurasiantimes.com/historic-japan-becomes-1st-country-ever-to-fire-electromagnetic/

Why is that unbelievable?

Railguns are very old news. Chemical energy is far more effective at
hurling projectiles than stored electrical energy, at about a 1000:1
ratio, and rail guns wear out a lot faster than gun barrels.

On Thu, 19 Oct 2023 09:18:34 -0700, John Larkin <jl@997PotHill.com>
wrote:

>On Thu, 19 Oct 2023 08:33:29 -0700 (PDT), Fred Bloggs
><bloggs.fredbloggs.fred@gmail.com> wrote:
>
>>According to a previous report published in Shephard Media, the ATLA railgun utilizes five megajoules (MJ), or five million joules (J), of charge energy. It can fire bullets at a speed of around 2,230m/s (Mach 6.5). 20 MJ of charge energy is what ATLA wants it to run on eventually.
>>
>>This is the unbelievable part:
>>
>>Additionally, interceptors can be fired by railguns at varying speeds. Operators can change the rate at which an interceptor moves by manipulating the amount of electrical power used. These choices would be based on how quickly incoming missiles approach.
>>
>><https://www.eurasiantimes.com/historic-japan-becomes-1st-country-ever-to-fire-electromagnetic/>
>
>Why is that unbelievable?
>
>Railguns are very old news. Chemical energy is far more effective at
>hurling projectiles than stored electrical energy, at about a 1000:1
>ratio, and rail guns wear out a lot faster than gun barrels.

The big railguns intended to destroy a tank or ship or ballistic
missile at great range very much had these problems, but it isn't
obvious that a much smaller railgun cannot work: "the weapon can
shoot 320g (or 0.7lb) 40mm steel rounds".

The advantage of a railgun is then rate of fire (hard to saturate) and
far smaller round volume (which isn't itself dangerous), so the
magazine can contain far more rounds before needing replenishment,
greatly improving the logistics.

Joe Gwinn

On Thursday, October 19, 2023 at 12:18:56 PM UTC-4, John Larkin wrote:
> On Thu, 19 Oct 2023 08:33:29 -0700 (PDT), Fred Bloggs
> <bloggs.fred...@gmail.com> wrote:
>
> >According to a previous report published in Shephard Media, the ATLA railgun utilizes five megajoules (MJ), or five million joules (J), of charge energy. It can fire bullets at a speed of around 2,230m/s (Mach 6.5). 20 MJ of charge energy is what ATLA wants it to run on eventually.
> >
> >This is the unbelievable part:
> >
> >Additionally, interceptors can be fired by railguns at varying speeds. Operators can change the rate at which an interceptor moves by manipulating the amount of electrical power used. These choices would be based on how quickly incoming missiles approach.
> >
> >https://www.eurasiantimes.com/historic-japan-becomes-1st-country-ever-to-fire-electromagnetic/
> Why is that unbelievable?
>
> Railguns are very old news. Chemical energy is far more effective at
> hurling projectiles than stored electrical energy, at about a 1000:1
> ratio, and rail guns wear out a lot faster than gun barrels.

By 'interceptor' I took it to mean missile, mostly ballistic but with in-flight adjustment for near sure hit.

On Thu, 19 Oct 2023 12:29:38 -0400, Joe Gwinn <joegwinn@comcast.net>
wrote:

>On Thu, 19 Oct 2023 09:18:34 -0700, John Larkin <jl@997PotHill.com>
>wrote:
>
>>On Thu, 19 Oct 2023 08:33:29 -0700 (PDT), Fred Bloggs
>><bloggs.fredbloggs.fred@gmail.com> wrote:
>>
>>>According to a previous report published in Shephard Media, the ATLA railgun utilizes five megajoules (MJ), or five million joules (J), of charge energy. It can fire bullets at a speed of around 2,230m/s (Mach 6.5). 20 MJ of charge energy is what ATLA wants it to run on eventually.
>>>
>>>This is the unbelievable part:
>>>
>>>Additionally, interceptors can be fired by railguns at varying speeds. Operators can change the rate at which an interceptor moves by manipulating the amount of electrical power used. These choices would be based on how quickly incoming missiles approach.
>>>
>>><https://www.eurasiantimes.com/historic-japan-becomes-1st-country-ever-to-fire-electromagnetic/>
>>
>>Why is that unbelievable?
>>
>>Railguns are very old news. Chemical energy is far more effective at
>>hurling projectiles than stored electrical energy, at about a 1000:1
>>ratio, and rail guns wear out a lot faster than gun barrels.
>
>The big railguns intended to destroy a tank or ship or ballistic
>missile at great range very much had these problems, but it isn't
>obvious that a much smaller railgun cannot work: "the weapon can
>shoot 320g (or 0.7lb) 40mm steel rounds".

Rihjt, great range requires terminal guidance, which is hard to do out
of a rail gun.

A guided missile can aim at the target and deliver gigajoules of
explosive energy.

>
>The advantage of a railgun is then rate of fire (hard to saturate) and
>far smaller round volume (which isn't itself dangerous), so the
>magazine can contain far more rounds before needing replenishment,
>greatly improving the logistics.
>
>Joe Gwinn

A good machine gun can fire many rounds per second.

https://247wallst.com/special-report/2023/07/16/fastest-firing-machine-guns-in-the-world/

The rail guns overheat and destroy their own barrels rapidly. And need
a gigantic power supply to fire very often.

It's like the difference between gasoline and batteries: orders of
magnitude different energy density.

On Thu, 19 Oct 2023 09:57:36 -0700, John Larkin <jl@997PotHill.com>
wrote:

>On Thu, 19 Oct 2023 12:29:38 -0400, Joe Gwinn <joegwinn@comcast.net>
>wrote:
>
>>On Thu, 19 Oct 2023 09:18:34 -0700, John Larkin <jl@997PotHill.com>
>>wrote:
>>
>>>On Thu, 19 Oct 2023 08:33:29 -0700 (PDT), Fred Bloggs
>>><bloggs.fredbloggs.fred@gmail.com> wrote:
>>>
>>>>According to a previous report published in Shephard Media, the ATLA railgun utilizes five megajoules (MJ), or five million joules (J), of charge energy. It can fire bullets at a speed of around 2,230m/s (Mach 6.5). 20 MJ of charge energy is what ATLA wants it to run on eventually.
>>>>
>>>>This is the unbelievable part:
>>>>
>>>>Additionally, interceptors can be fired by railguns at varying speeds. Operators can change the rate at which an interceptor moves by manipulating the amount of electrical power used. These choices would be based on how quickly incoming missiles approach.
>>>>
>>>><https://www.eurasiantimes.com/historic-japan-becomes-1st-country-ever-to-fire-electromagnetic/>
>>>
>>>Why is that unbelievable?
>>>
>>>Railguns are very old news. Chemical energy is far more effective at
>>>hurling projectiles than stored electrical energy, at about a 1000:1
>>>ratio, and rail guns wear out a lot faster than gun barrels.
>>
>>The big railguns intended to destroy a tank or ship or ballistic
>>missile at great range very much had these problems, but it isn't
>>obvious that a much smaller railgun cannot work: "the weapon can
>>shoot 320g (or 0.7lb) 40mm steel rounds".
>
>Right, great range requires terminal guidance, which is hard to do out
>of a rail gun.
>
>A guided missile can aim at the target and deliver gigajoules of
>explosive energy.

Yes.

>>
>>The advantage of a railgun is then rate of fire (hard to saturate) and
>>far smaller round volume (which isn't itself dangerous), so the
>>magazine can contain far more rounds before needing replenishment,
>>greatly improving the logistics.
>>
>
>A good machine gun can fire many rounds per second.
>
>https://247wallst.com/special-report/2023/07/16/fastest-firing-machine-guns-in-the-world/
>
>The rail guns overheat and destroy their own barrels rapidly. And need
>a gigantic power supply to fire very often.
>
>It's like the difference between gasoline and batteries: orders of
>magnitude different energy density.

The difference is that it's hard for a gun to make bullets fly faster
than the speed of sound in the hot gases propelling the shell down the
barrel.

Joe Gwinn

On Thu, 19 Oct 2023 15:21:21 -0400, Joe Gwinn <joegwinn@comcast.net>
wrote:

>On Thu, 19 Oct 2023 09:57:36 -0700, John Larkin <jl@997PotHill.com>
>wrote:
>
>>On Thu, 19 Oct 2023 12:29:38 -0400, Joe Gwinn <joegwinn@comcast.net>
>>wrote:
>>
>>>On Thu, 19 Oct 2023 09:18:34 -0700, John Larkin <jl@997PotHill.com>
>>>wrote:
>>>
>>>>On Thu, 19 Oct 2023 08:33:29 -0700 (PDT), Fred Bloggs
>>>><bloggs.fredbloggs.fred@gmail.com> wrote:
>>>>
>>>>>According to a previous report published in Shephard Media, the ATLA railgun utilizes five megajoules (MJ), or five million joules (J), of charge energy. It can fire bullets at a speed of around 2,230m/s (Mach 6.5). 20 MJ of charge energy is what ATLA wants it to run on eventually.
>>>>>
>>>>>This is the unbelievable part:
>>>>>
>>>>>Additionally, interceptors can be fired by railguns at varying speeds. Operators can change the rate at which an interceptor moves by manipulating the amount of electrical power used. These choices would be based on how quickly incoming missiles approach.
>>>>>
>>>>><https://www.eurasiantimes.com/historic-japan-becomes-1st-country-ever-to-fire-electromagnetic/>
>>>>
>>>>Why is that unbelievable?
>>>>
>>>>Railguns are very old news. Chemical energy is far more effective at
>>>>hurling projectiles than stored electrical energy, at about a 1000:1
>>>>ratio, and rail guns wear out a lot faster than gun barrels.
>>>
>>>The big railguns intended to destroy a tank or ship or ballistic
>>>missile at great range very much had these problems, but it isn't
>>>obvious that a much smaller railgun cannot work: "the weapon can
>>>shoot 320g (or 0.7lb) 40mm steel rounds".
>>
>>Right, great range requires terminal guidance, which is hard to do out
>>of a rail gun.
>>
>>A guided missile can aim at the target and deliver gigajoules of
>>explosive energy.
>
>Yes.
>
>>>
>>>The advantage of a railgun is then rate of fire (hard to saturate) and
>>>far smaller round volume (which isn't itself dangerous), so the
>>>magazine can contain far more rounds before needing replenishment,
>>>greatly improving the logistics.
>>>
>>
>>A good machine gun can fire many rounds per second.
>>
>>https://247wallst.com/special-report/2023/07/16/fastest-firing-machine-guns-in-the-world/
>>
>>The rail guns overheat and destroy their own barrels rapidly. And need
>>a gigantic power supply to fire very often.
>>
>>It's like the difference between gasoline and batteries: orders of
>>magnitude different energy density.
>
>The difference is that it's hard for a gun to make bullets fly faster
>than the speed of sound in the hot gases propelling the shell down the
>barrel.
>
>Joe Gwinn

https://en.wikipedia.org/wiki/.220_Swift

john larkin <jl@650pot.com> wrote:
> On Thu, 19 Oct 2023 15:21:21 -0400, Joe Gwinn <joegwinn@comcast.net>
> wrote:
>
>> On Thu, 19 Oct 2023 09:57:36 -0700, John Larkin <jl@997PotHill.com>
>> wrote:
>>
>>> On Thu, 19 Oct 2023 12:29:38 -0400, Joe Gwinn <joegwinn@comcast.net>
>>> wrote:
>>>
>>>> On Thu, 19 Oct 2023 09:18:34 -0700, John Larkin <jl@997PotHill.com>
>>>> wrote:
>>>>
>>>>> On Thu, 19 Oct 2023 08:33:29 -0700 (PDT), Fred Bloggs
>>>>> <bloggs.fredbloggs.fred@gmail.com> wrote:
>>>>>
>>>>>> According to a previous report published in Shephard Media, the ATLA
>>>>>> railgun utilizes five megajoules (MJ), or five million joules (J),
>>>>>> of charge energy. It can fire bullets at a speed of around 2,230m/s
>>>>>> (Mach 6.5). 20 MJ of charge energy is what ATLA wants it to run on eventually.
>>>>>>
>>>>>> This is the unbelievable part:
>>>>>>
>>>>>> Additionally, interceptors can be fired by railguns at varying
>>>>>> speeds. Operators can change the rate at which an interceptor moves
>>>>>> by manipulating the amount of electrical power used. These choices
>>>>>> would be based on how quickly incoming missiles approach.
>>>>>>
>>>>>> <https://www.eurasiantimes.com/historic-japan-becomes-1st-country-ever-to-fire-electromagnetic/>
>>>>>
>>>>> Why is that unbelievable?
>>>>>
>>>>> Railguns are very old news. Chemical energy is far more effective at
>>>>> hurling projectiles than stored electrical energy, at about a 1000:1
>>>>> ratio, and rail guns wear out a lot faster than gun barrels.
>>>>
>>>> The big railguns intended to destroy a tank or ship or ballistic
>>>> missile at great range very much had these problems, but it isn't
>>>> obvious that a much smaller railgun cannot work: "the weapon can
>>>> shoot 320g (or 0.7lb) 40mm steel rounds".
>>>
>>> Right, great range requires terminal guidance, which is hard to do out
>>> of a rail gun.
>>>
>>> A guided missile can aim at the target and deliver gigajoules of
>>> explosive energy.
>>
>> Yes.
>>
>>>>
>>>> The advantage of a railgun is then rate of fire (hard to saturate) and
>>>> far smaller round volume (which isn't itself dangerous), so the
>>>> magazine can contain far more rounds before needing replenishment,
>>>> greatly improving the logistics.
>>>>
>>>
>>> A good machine gun can fire many rounds per second.
>>>
>>> https://247wallst.com/special-report/2023/07/16/fastest-firing-machine-guns-in-the-world/
>>>
>>> The rail guns overheat and destroy their own barrels rapidly. And need
>>> a gigantic power supply to fire very often.
>>>
>>> It's like the difference between gasoline and batteries: orders of
>>> magnitude different energy density.
>>
>> The difference is that it's hard for a gun to make bullets fly faster
>> than the speed of sound in the hot gases propelling the shell down the
>> barrel.
>>
>> Joe Gwinn
>
> https://en.wikipedia.org/wiki/.220_Swift
>
>
That’s just supersonic at 300K, but the speed of sound goes like sqrt(T).

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs Principal Consultant ElectroOptical Innovations LLC /
Hobbs ElectroOptics Optics, Electro-optics, Photonics, Analog Electronics

On Thu, 19 Oct 2023 13:21:44 -0700, john larkin <jl@650pot.com> wrote:

>On Thu, 19 Oct 2023 15:21:21 -0400, Joe Gwinn <joegwinn@comcast.net>
>wrote:
>
>>On Thu, 19 Oct 2023 09:57:36 -0700, John Larkin <jl@997PotHill.com>
>>wrote:
>>
>>>On Thu, 19 Oct 2023 12:29:38 -0400, Joe Gwinn <joegwinn@comcast.net>
>>>wrote:
>>>
>>>>On Thu, 19 Oct 2023 09:18:34 -0700, John Larkin <jl@997PotHill.com>
>>>>wrote:
>>>>
>>>>>On Thu, 19 Oct 2023 08:33:29 -0700 (PDT), Fred Bloggs
>>>>><bloggs.fredbloggs.fred@gmail.com> wrote:
>>>>>
>>>>>>According to a previous report published in Shephard Media, the ATLA railgun utilizes five megajoules (MJ), or five million joules (J), of charge energy. It can fire bullets at a speed of around 2,230m/s (Mach 6.5). 20 MJ of charge energy is what ATLA wants it to run on eventually.
>>>>>>
>>>>>>This is the unbelievable part:
>>>>>>
>>>>>>Additionally, interceptors can be fired by railguns at varying speeds. Operators can change the rate at which an interceptor moves by manipulating the amount of electrical power used. These choices would be based on how quickly incoming missiles approach.
>>>>>>
>>>>>><https://www.eurasiantimes.com/historic-japan-becomes-1st-country-ever-to-fire-electromagnetic/>
>>>>>
>>>>>Why is that unbelievable?
>>>>>
>>>>>Railguns are very old news. Chemical energy is far more effective at
>>>>>hurling projectiles than stored electrical energy, at about a 1000:1
>>>>>ratio, and rail guns wear out a lot faster than gun barrels.
>>>>
>>>>The big railguns intended to destroy a tank or ship or ballistic
>>>>missile at great range very much had these problems, but it isn't
>>>>obvious that a much smaller railgun cannot work: "the weapon can
>>>>shoot 320g (or 0.7lb) 40mm steel rounds".
>>>
>>>Right, great range requires terminal guidance, which is hard to do out
>>>of a rail gun.
>>>
>>>A guided missile can aim at the target and deliver gigajoules of
>>>explosive energy.
>>
>>Yes.
>>
>>>>
>>>>The advantage of a railgun is then rate of fire (hard to saturate) and
>>>>far smaller round volume (which isn't itself dangerous), so the
>>>>magazine can contain far more rounds before needing replenishment,
>>>>greatly improving the logistics.
>>>>
>>>
>>>A good machine gun can fire many rounds per second.
>>>
>>>https://247wallst.com/special-report/2023/07/16/fastest-firing-machine-guns-in-the-world/
>>>
>>>The rail guns overheat and destroy their own barrels rapidly. And need
>>>a gigantic power supply to fire very often.
>>>
>>>It's like the difference between gasoline and batteries: orders of
>>>magnitude different energy density.
>>
>>The difference is that it's hard for a gun to make bullets fly faster
>>than the speed of sound in the hot gases propelling the shell down the
>>barrel.
>>
>>Joe Gwinn
>
>https://en.wikipedia.org/wiki/.220_Swift

That's pretty small for taking bigger things out at distance.

I do know that the problem is that the speed of sound of the
propelling gases matters, but I don't recall the ratio. Lots is
published concerning the need to use pressurized helium or hydrogen
when launching very high speed projectiles. This was done with a
vacuum in the barrel ahead of the bullet and a burst membrane behind.
Joe Gwinn

On Thu, 19 Oct 2023 22:19:47 -0000 (UTC), Phil Hobbs
<pcdhSpamMeSenseless@electrooptical.net> wrote:

>john larkin <jl@650pot.com> wrote:
>> On Thu, 19 Oct 2023 15:21:21 -0400, Joe Gwinn <joegwinn@comcast.net>
>> wrote:
>>
>>> On Thu, 19 Oct 2023 09:57:36 -0700, John Larkin <jl@997PotHill.com>
>>> wrote:
>>>
>>>> On Thu, 19 Oct 2023 12:29:38 -0400, Joe Gwinn <joegwinn@comcast.net>
>>>> wrote:
>>>>
>>>>> On Thu, 19 Oct 2023 09:18:34 -0700, John Larkin <jl@997PotHill.com>
>>>>> wrote:
>>>>>
>>>>>> On Thu, 19 Oct 2023 08:33:29 -0700 (PDT), Fred Bloggs
>>>>>> <bloggs.fredbloggs.fred@gmail.com> wrote:
>>>>>>
>>>>>>> According to a previous report published in Shephard Media, the ATLA
>>>>>>> railgun utilizes five megajoules (MJ), or five million joules (J),
>>>>>>> of charge energy. It can fire bullets at a speed of around 2,230m/s
>>>>>>> (Mach 6.5). 20 MJ of charge energy is what ATLA wants it to run on eventually.
>>>>>>>
>>>>>>> This is the unbelievable part:
>>>>>>>
>>>>>>> Additionally, interceptors can be fired by railguns at varying
>>>>>>> speeds. Operators can change the rate at which an interceptor moves
>>>>>>> by manipulating the amount of electrical power used. These choices
>>>>>>> would be based on how quickly incoming missiles approach.
>>>>>>>
>>>>>>> <https://www.eurasiantimes.com/historic-japan-becomes-1st-country-ever-to-fire-electromagnetic/>
>>>>>>
>>>>>> Why is that unbelievable?
>>>>>>
>>>>>> Railguns are very old news. Chemical energy is far more effective at
>>>>>> hurling projectiles than stored electrical energy, at about a 1000:1
>>>>>> ratio, and rail guns wear out a lot faster than gun barrels.
>>>>>
>>>>> The big railguns intended to destroy a tank or ship or ballistic
>>>>> missile at great range very much had these problems, but it isn't
>>>>> obvious that a much smaller railgun cannot work: "the weapon can
>>>>> shoot 320g (or 0.7lb) 40mm steel rounds".
>>>>
>>>> Right, great range requires terminal guidance, which is hard to do out
>>>> of a rail gun.
>>>>
>>>> A guided missile can aim at the target and deliver gigajoules of
>>>> explosive energy.
>>>
>>> Yes.
>>>
>>>>>
>>>>> The advantage of a railgun is then rate of fire (hard to saturate) and
>>>>> far smaller round volume (which isn't itself dangerous), so the
>>>>> magazine can contain far more rounds before needing replenishment,
>>>>> greatly improving the logistics.
>>>>>
>>>>
>>>> A good machine gun can fire many rounds per second.
>>>>
>>>> https://247wallst.com/special-report/2023/07/16/fastest-firing-machine-guns-in-the-world/
>>>>
>>>> The rail guns overheat and destroy their own barrels rapidly. And need
>>>> a gigantic power supply to fire very often.
>>>>
>>>> It's like the difference between gasoline and batteries: orders of
>>>> magnitude different energy density.
>>>
>>> The difference is that it's hard for a gun to make bullets fly faster
>>> than the speed of sound in the hot gases propelling the shell down the
>>> barrel.
>>>
>>> Joe Gwinn
>>
>> https://en.wikipedia.org/wiki/.220_Swift
>>
>>
>That’s just supersonic at 300K, but the speed of sound goes like sqrt(T).
>
>Cheers
>
>Phil Hobbs

Given some gunpowder squashed into a container and ignited, is the
result a gas?

On Friday, October 20, 2023 at 11:27:33 AM UTC+11, John Larkin wrote:
> On Thu, 19 Oct 2023 22:19:47 -0000 (UTC), Phil Hobbs
> <pcdhSpamM...@electrooptical.net> wrote:
>
> >john larkin <j...@650pot.com> wrote:
> >> On Thu, 19 Oct 2023 15:21:21 -0400, Joe Gwinn <joeg...@comcast.net>
> >> wrote:
> >>
> >>> On Thu, 19 Oct 2023 09:57:36 -0700, John Larkin <j...@997PotHill.com>
> >>> wrote:
> >>>
> >>>> On Thu, 19 Oct 2023 12:29:38 -0400, Joe Gwinn <joeg...@comcast.net>
> >>>> wrote:
> >>>>
> >>>>> On Thu, 19 Oct 2023 09:18:34 -0700, John Larkin <j...@997PotHill.com>
> >>>>> wrote:
> >>>>>
> >>>>>> On Thu, 19 Oct 2023 08:33:29 -0700 (PDT), Fred Bloggs
> >>>>>> <bloggs.fred...@gmail.com> wrote:
> >>>>>>
> >>>>>>> According to a previous report published in Shephard Media, the ATLA
> >>>>>>> railgun utilizes five megajoules (MJ), or five million joules (J),
> >>>>>>> of charge energy. It can fire bullets at a speed of around 2,230m/s
> >>>>>>> (Mach 6.5). 20 MJ of charge energy is what ATLA wants it to run on eventually.
> >>>>>>>
> >>>>>>> This is the unbelievable part:
> >>>>>>>
> >>>>>>> Additionally, interceptors can be fired by railguns at varying
> >>>>>>> speeds. Operators can change the rate at which an interceptor moves
> >>>>>>> by manipulating the amount of electrical power used. These choices
> >>>>>>> would be based on how quickly incoming missiles approach.
> >>>>>>>
> >>>>>>> <https://www.eurasiantimes.com/historic-japan-becomes-1st-country-ever-to-fire-electromagnetic/>
> >>>>>>
> >>>>>> Why is that unbelievable?
> >>>>>>
> >>>>>> Railguns are very old news. Chemical energy is far more effective at
> >>>>>> hurling projectiles than stored electrical energy, at about a 1000:1
> >>>>>> ratio, and rail guns wear out a lot faster than gun barrels.
> >>>>>
> >>>>> The big railguns intended to destroy a tank or ship or ballistic
> >>>>> missile at great range very much had these problems, but it isn't
> >>>>> obvious that a much smaller railgun cannot work: "the weapon can
> >>>>> shoot 320g (or 0.7lb) 40mm steel rounds".
> >>>>
> >>>> Right, great range requires terminal guidance, which is hard to do out
> >>>> of a rail gun.
> >>>>
> >>>> A guided missile can aim at the target and deliver gigajoules of
> >>>> explosive energy.
> >>>
> >>> Yes.
> >>>
> >>>>>
> >>>>> The advantage of a railgun is then rate of fire (hard to saturate) and
> >>>>> far smaller round volume (which isn't itself dangerous), so the
> >>>>> magazine can contain far more rounds before needing replenishment,
> >>>>> greatly improving the logistics.
> >>>>>
> >>>>
> >>>> A good machine gun can fire many rounds per second.
> >>>>
> >>>> https://247wallst.com/special-report/2023/07/16/fastest-firing-machine-guns-in-the-world/
> >>>>
> >>>> The rail guns overheat and destroy their own barrels rapidly. And need
> >>>> a gigantic power supply to fire very often.
> >>>>
> >>>> It's like the difference between gasoline and batteries: orders of
> >>>> magnitude different energy density.
> >>>
> >>> The difference is that it's hard for a gun to make bullets fly faster
> >>> than the speed of sound in the hot gases propelling the shell down the
> >>> barrel.
> >>>
> >>> Joe Gwinn
> >>
> >> https://en.wikipedia.org/wiki/.220_Swift
> >>
> >>
> >That’s just supersonic at 300K, but the speed of sound goes like sqrt(T).
>
> Given some gunpowder squashed into a container and ignited, is the result a gas?

Classically gun powder was a mixture of charcoal (carbon) saltpeter (sodium/potassium nitrate) and sulphur.

It burns to CO2, SO2 and nitrogen - which are gases - and sodium and potassium oxides (which aren't) so it's a rather dusty gas, but the gas production was what was important. John Larkin did skip some of his chemistry lessons at Tulane.

--
Bill Sloman, Sydney

On 2023-10-20, John Larkin <jl@997PotHill.com> wrote:
> On Thu, 19 Oct 2023 22:19:47 -0000 (UTC), Phil Hobbs
><pcdhSpamMeSenseless@electrooptical.net> wrote:
>
>>john larkin <jl@650pot.com> wrote:
>>> On Thu, 19 Oct 2023 15:21:21 -0400, Joe Gwinn <joegwinn@comcast.net>
>>> wrote:
>>>
>>>> On Thu, 19 Oct 2023 09:57:36 -0700, John Larkin <jl@997PotHill.com>
>>>> wrote:
>>>>
>>>>> On Thu, 19 Oct 2023 12:29:38 -0400, Joe Gwinn <joegwinn@comcast.net>
>>>>> wrote:
>>>>>
>>>>>> On Thu, 19 Oct 2023 09:18:34 -0700, John Larkin <jl@997PotHill.com>
>>>>>> wrote:
>>>>>>
>>>>>>> On Thu, 19 Oct 2023 08:33:29 -0700 (PDT), Fred Bloggs
>>>>>>> <bloggs.fredbloggs.fred@gmail.com> wrote:
>>>>>>>
>>>>>>>> According to a previous report published in Shephard Media, the ATLA
>>>>>>>> railgun utilizes five megajoules (MJ), or five million joules (J),
>>>>>>>> of charge energy. It can fire bullets at a speed of around 2,230m/s
>>>>>>>> (Mach 6.5). 20 MJ of charge energy is what ATLA wants it to run on eventually.
>>>>>>>>
>>>>>>>> This is the unbelievable part:
>>>>>>>>
>>>>>>>> Additionally, interceptors can be fired by railguns at varying
>>>>>>>> speeds. Operators can change the rate at which an interceptor moves
>>>>>>>> by manipulating the amount of electrical power used. These choices
>>>>>>>> would be based on how quickly incoming missiles approach.
>>>>>>>>
>>>>>>>> <https://www.eurasiantimes.com/historic-japan-becomes-1st-country-ever-to-fire-electromagnetic/>
>>>>>>>
>>>>>>> Why is that unbelievable?
>>>>>>>
>>>>>>> Railguns are very old news. Chemical energy is far more effective at
>>>>>>> hurling projectiles than stored electrical energy, at about a 1000:1
>>>>>>> ratio, and rail guns wear out a lot faster than gun barrels.
>>>>>>
>>>>>> The big railguns intended to destroy a tank or ship or ballistic
>>>>>> missile at great range very much had these problems, but it isn't
>>>>>> obvious that a much smaller railgun cannot work: "the weapon can
>>>>>> shoot 320g (or 0.7lb) 40mm steel rounds".
>>>>>
>>>>> Right, great range requires terminal guidance, which is hard to do out
>>>>> of a rail gun.
>>>>>
>>>>> A guided missile can aim at the target and deliver gigajoules of
>>>>> explosive energy.
>>>>
>>>> Yes.
>>>>
>>>>>>
>>>>>> The advantage of a railgun is then rate of fire (hard to saturate) and
>>>>>> far smaller round volume (which isn't itself dangerous), so the
>>>>>> magazine can contain far more rounds before needing replenishment,
>>>>>> greatly improving the logistics.
>>>>>>
>>>>>
>>>>> A good machine gun can fire many rounds per second.
>>>>>
>>>>> https://247wallst.com/special-report/2023/07/16/fastest-firing-machine-guns-in-the-world/
>>>>>
>>>>> The rail guns overheat and destroy their own barrels rapidly. And need
>>>>> a gigantic power supply to fire very often.
>>>>>
>>>>> It's like the difference between gasoline and batteries: orders of
>>>>> magnitude different energy density.
>>>>
>>>> The difference is that it's hard for a gun to make bullets fly faster
>>>> than the speed of sound in the hot gases propelling the shell down the
>>>> barrel.
>>>>
>>>> Joe Gwinn
>>>
>>> https://en.wikipedia.org/wiki/.220_Swift
>>>
>>>
>>That’s just supersonic at 300K, but the speed of sound goes like sqrt(T).
>>
>>Cheers
>>
>>Phil Hobbs
>
> Given some gunpowder squashed into a container and ignited, is the
> result a gas?

Flames are mostly gas, there's a little plamsa, but it's mostly hot gas.

--
Jasen.
🇺🇦 Слава Україні

On October 19, Fred Bloggs wrote:
> According to a previous report published in Shephard Media, the ATLA railgun utilizes
> five megajoules (MJ), or five million joules (J), of charge energy. It can fire bullets at
> a speed of around 2,230m/s (Mach 6.5). 20 MJ of charge energy is what ATLA wants it
> to run on eventually.
> https://www.eurasiantimes.com/historic-japan-becomes-1st-country-ever-to-fire-electromagnetic/

https://www.wsj.com/articles/a-first-look-at-americas-supergun-1464359194

--
Rich

On Saturday, October 21, 2023 at 8:52:01 PM UTC-4, RichD wrote:
> On October 19, Fred Bloggs wrote:
> > According to a previous report published in Shephard Media, the ATLA railgun utilizes
> > five megajoules (MJ), or five million joules (J), of charge energy. It can fire bullets at
> > a speed of around 2,230m/s (Mach 6.5). 20 MJ of charge energy is what ATLA wants it
> > to run on eventually.
> > https://www.eurasiantimes.com/historic-japan-becomes-1st-country-ever-to-fire-electromagnetic/
>
> https://www.wsj.com/articles/a-first-look-at-americas-supergun-1464359194

That's a 7 year old article, which is 1) totally obsolete and 2) a cheap shill for the military spending. Around the time of the article, they were putting $500M into the program, an amount they admitted to, meaning it was probably more like $1B, and the whole thing was eventually a failure. All the demonstrations they publicized on video are land based test site experiments.

Major shortfalls:

1) never could meet the 10 shots per minute requirement,

2) still had not overcome material erosion of the rail, which would result in costly and time consuming changeout too frequently for operational purposes,

3) system required the use of a $38k guided round [ far cry from 'dollar a shot' initial selling point ] to meet the accuracy performance at range, a ballistic projectile wouldn't cut it, shipborne system have to contend with pitch, yaw, and roll, and the ocean environment tends to be windy,

4) super expensive backfit of high performance, high capacity, power generation required wherever it would be installed.

5) lots of other things...

The only selling point they had for this thing was to eliminate the vulnerability of ammunition stores on the ship, harkening back to some of those humongous WW2 British Navy disaster battleship explosions where they lost 4,000 sailors in a single blast. Looks like that wasn't such a priority anymore.

>
> --
> Rich

On 22/10/2023 01:51, RichD wrote:
> On October 19, Fred Bloggs wrote:
>> According to a previous report published in Shephard Media, the ATLA railgun utilizes
>> five megajoules (MJ), or five million joules (J), of charge energy. It can fire bullets at
>> a speed of around 2,230m/s (Mach 6.5). 20 MJ of charge energy is what ATLA wants it
>> to run on eventually.
>> https://www.eurasiantimes.com/historic-japan-becomes-1st-country-ever-to-fire-electromagnetic/
>
> https://www.wsj.com/articles/a-first-look-at-americas-supergun-1464359194

<https://www.defensenews.com/naval/2021/07/01/us-navy-ditches-futuristic-railgun-eyes-hypersonic-missiles/>

--

Jeff

On Sun, 22 Oct 2023 08:07:17 -0700 (PDT), Fred Bloggs
<bloggs.fredbloggs.fred@gmail.com> wrote:

>On Saturday, October 21, 2023 at 8:52:01?PM UTC-4, RichD wrote:
>> On October 19, Fred Bloggs wrote:
>> > According to a previous report published in Shephard Media, the ATLA railgun utilizes
>> > five megajoules (MJ), or five million joules (J), of charge energy. It can fire bullets at
>> > a speed of around 2,230m/s (Mach 6.5). 20 MJ of charge energy is what ATLA wants it
>> > to run on eventually.
>> > https://www.eurasiantimes.com/historic-japan-becomes-1st-country-ever-to-fire-electromagnetic/
>>
>> https://www.wsj.com/articles/a-first-look-at-americas-supergun-1464359194
>
>That's a 7 year old article, which is 1) totally obsolete and 2) a cheap shill for the military spending. Around the time of the article, they were putting $500M into the program, an amount they admitted to, meaning it was probably more like $1B, and the whole thing was eventually a failure. All the demonstrations they publicized on video are land based test site experiments.
>
>Major shortfalls:
>
>1) never could meet the 10 shots per minute requirement,
>
>2) still had not overcome material erosion of the rail, which would result in costly and time consuming changeout too frequently for operational purposes,
>
>3) system required the use of a $38k guided round [ far cry from 'dollar a shot' initial selling point ] to meet the accuracy performance at range, a ballistic projectile wouldn't cut it, shipborne system have to contend with pitch, yaw, and roll, and the ocean environment tends to be windy,
>
>4) super expensive backfit of high performance, high capacity, power generation required wherever it would be installed.
>
>5) lots of other things...
>
>The only selling point they had for this thing was to eliminate the vulnerability of ammunition stores on the ship, harkening back to some of those humongous WW2 British Navy disaster battleship explosions where they lost 4,000 sailors in a single blast. Looks like that wasn't such a priority anymore.
>
>

Whatever energy source launches projectiles, it has to be stored on
the ship.

On Thursday, October 26, 2023 at 6:41:20 AM UTC-4, Jeff Layman wrote:
> On 22/10/2023 01:51, RichD wrote:
> > On October 19, Fred Bloggs wrote:
> >> According to a previous report published in Shephard Media, the ATLA railgun utilizes
> >> five megajoules (MJ), or five million joules (J), of charge energy. It can fire bullets at
> >> a speed of around 2,230m/s (Mach 6.5). 20 MJ of charge energy is what ATLA wants it
> >> to run on eventually.
> >> https://www.eurasiantimes.com/historic-japan-becomes-1st-country-ever-to-fire-electromagnetic/
> >
> > https://www.wsj.com/articles/a-first-look-at-americas-supergun-1464359194
> <https://www.defensenews.com/naval/2021/07/01/us-navy-ditches-futuristic-railgun-eyes-hypersonic-missiles/>

Like any of that was a surprise they couldn't see coming before they spent a billion on it. Total ripoff.

And the 'advanced' gun system for the zumwalt destroyers was cancelled because the projectiles were coming in at $300k per copy. Like any of that was a surprise either. The gun-less navy destroyers- must be a first.

The rest the article is typical media garbage about moving on to even newer technology to spend a bundle on ...

>
> --
>
> Jeff

On October 22, Fred Bloggs wrote:
> The only selling point they had for this thing was to eliminate the vulnerability of
> ammunition stores on the ship, harkening back to some of those humongous
> WW2 British Navy disaster battleship explosions where they lost 4,000 sailors
> in a single blast.

Quite. And the U.S. navy was a prime beneficiary of such tactics.
What sank the japanese carriers at the battle of Midway?

--
Rich

On Friday, October 27, 2023 at 5:13:36 PM UTC-4, RichD wrote:
> On October 22, Fred Bloggs wrote:
> > The only selling point they had for this thing was to eliminate the vulnerability of
> > ammunition stores on the ship, harkening back to some of those humongous
> > WW2 British Navy disaster battleship explosions where they lost 4,000 sailors
> > in a single blast.
> Quite. And the U.S. navy was a prime beneficiary of such tactics.
> What sank the japanese carriers at the battle of Midway?

Dive bombers

They also sent a squadron of torpedo bombers but they were ineffective.

https://en.wikipedia.org/wiki/Douglas_SBD_Dauntless

>
> --
> Rich

On October 27, Fred Bloggs wrote:
>>> The only selling point they had for this thing was to eliminate the vulnerability of
>>> ammunition stores on the ship, harkening back to some of those humongous
>>> WW2 British Navy disaster battleship explosions where they lost 4,000 sailors
>>> in a single blast.
>
>> Quite. And the U.S. navy was a prime beneficiary of such tactics.
>> What sank the japanese carriers at the battle of Midway?
>
> Dive bombers
You miss the point. The carriers were loaded with their own ordnance
below deck, as their planes were in process of reloading. By grace of
Allah, the U.S. bombers arrived at the ideal moment. Their bombs
ignited the fuel like a giant hibachi.

For anyone interested in military history, there's an excellent vid on
Youtube, displaying the battle from admiral Nagumo's point of view,
in his headquarters, as it unfolded. "the fog of war"

--
Rich

On Saturday, October 28, 2023 at 2:13:30 PM UTC-4, RichD wrote:
> On October 27, Fred Bloggs wrote:
> >>> The only selling point they had for this thing was to eliminate the vulnerability of
> >>> ammunition stores on the ship, harkening back to some of those humongous
> >>> WW2 British Navy disaster battleship explosions where they lost 4,000 sailors
> >>> in a single blast.
> >
> >> Quite. And the U.S. navy was a prime beneficiary of such tactics.
> >> What sank the japanese carriers at the battle of Midway?
> >
> > Dive bombers
> You miss the point. The carriers were loaded with their own ordnance
> below deck, as their planes were in process of reloading. By grace of
> Allah, the U.S. bombers arrived at the ideal moment. Their bombs
> ignited the fuel like a giant hibachi.

The original mission of the IJN was to destroy the US air station on Midway.. The discovery of a USN carrier group within range of them was a complete surprise. The Japanese admiral was conflicted with either continuing the bombing on Midway or going after the carrier group. The one mission required the aircraft be loaded with heavy bombs, and the second torpedoes. Japanese admiral decided to go all in on the selected mission, and apparently didn't keep any combat patrol aircraft in the air to protect his carriers. Dive bombers, of whatever make, are slow lumbering sitting ducks for fighter aircraft. IJN was in process of changing out the armament and fueling aircraft when the U.S. dive bomber attack took place. The big carriers were an easy target. A 500 pounder detonating in a closed space below deck was a horrendous concussion. No one was alive to put out the fuel fires. There's no mention in the historical narratives of sympathetic (so-called) explosions of a giant magazines of bombs going off, all they say is the carriers caught fire and the crews abandoned ship. Which was all the same because the Japanese weren't going to be able to rebuild a heavily damaged ship, the carriers were out of the war for the duration, afloat or on the bottom.

>
> For anyone interested in military history, there's an excellent vid on
> Youtube, displaying the battle from admiral Nagumo's point of view,
> in his headquarters, as it unfolded. "the fog of war"
>
> --
> Rich